Plant communities of the Riversdale Plain

Abstract

The vegetation of the Riversdale coastal plain was classified and described using Campbell’s (1985) approach. Data collected included a subset of Campbell’s structural and higher taxon characters, as well as dominant (> 10% cover) species, which would enable the recognition of communities to at least the subseries level in his hierarchy. The classification was produced using the Braun-Blanquet method of table sorting. Twenty zonal communities, at various hierarchical levels, were recognized and mapped. Non-fynbos communities included Afromontane Forest, Eastern Forest and Thicket, Kaffrarian Succulent Thicket and Dune Thicket Series in the Forest and Thicket Group, and Renoster Shrubland. Fynbos communities were Mesotrophic Grassy Fynbos, three subseries of Asteraceous Fynbos (Mesotrophic, Dune and Oligotrophic), Azonal Restioid Fynbos, Wet Proteoid Fynbos, Dry Proteoid Fynbos and six types of Mesic Proteoid Fynbos. The vegetation types could all be integrated into Campbell’s Fynbos Biome mountain vegetation concepts and modifications based on work on the Agulhas plain. The mapped communities are adequate for conservation planning and comprise an essential descriptive basis for future studies. The data on Proteaceae cover corresponds well to that of the Restionaceae for Proteoid Fynbos — together the two families comprise the only groups which could be used for a classification without requiring extensive floristic studies. Die plantegroei van die Riversdale seevlakte word geklassifiseer en beskryf deur gebruik te maak van Campbell (1985) se benadering. Die data wat versamel is, bevat ’n subgroup van Campbell se strukturele en hoër takson-karakters, sowel as dominante (> 10% bedekking) spesies, wat die uitkenning van gemeenskappe tot op die subserievlak in sy hierargie moontlik maak. Die klassifikasie is teweeg gebring deur gebruik te maak van die Braun-Blanquet metode van tabel-sortering. Twintig streeksgemeenskappe is op verskeie hierargiese vlakke geïdentifiseer en gekarteer. Nie-fynbos-gemeenskappe het die volgende ingesluit: Afromontane Woude, Oostelike Woud en Ruigte, Kaffrariese Sukkulente Ruigte en Duine Ruigte Series, in die Woud en Ruigte Groep, en Renosterstruikveld. Fynbos-gemeenskappe het Mesotrofiese Grasagtige Fynbos, drie subseries van Komposiet-Fynbos (Mesotrofiese, Duine en Oligotrofiese), Azonal Restioïede-Fynbos, Nat Proteoïede-Fynbos, Droog Proteoïede-Fynbos en ses tipes van Mesiese-Proteoïede-Fynbos ingesluit. Die gemeenskappe kan almal met Campbell se Fynbos-Bioom-plantegroeikonsepteen modifikasies daarop, gebaseer op werk in die Agulhasvlakte, geïntegreer word. Die gekarteerde gemeenskappe is voldoende vir die beplanning van bewaringsaksies en behels ’n essensiële beskrywende basis vir toekomstige studies. Die data oor Proteaceae-bedekking vergelyk goed met die van die Restionaceae in Proteoïede-Fynbos— gesamentlik is die twee families die enigste groepe wat vir ’n klassifikasie gebruik word sonder om verdere floristiese studies uit te voer.